Cooled mandrel for winding a strip product

ABSTRACT

The invention concerns a cooled mandrel for winding a band-type product into a coil, including a set of adjacent segments ( 2 ) mounted to slide radially on a central shaft ( 1 ) and fitted each of a cooling circuit ( 24, 24 ′) having two orifices, respectively an inlet orifice ( 75 ) and an outlet orifice ( 75 ′), connected each, by a connection fitting ( 7, 7 ′) having a variable length, to a supply ( 5 ) or exhaust ( 5 ′) duct, respectively of a heat exchanging fluid.  
     According to the invention, the linking fittings ( 7, 7 ′) corresponding to each segment ( 2 ) are connected to a distribution part ( 6 ) threaded on a lateral face ( 13 ′) of the shaft ( 1 ), wherein emerge transversally both ducts, respectively the supply duct ( 5 ) and the exhaust duct ( 5 ′), which are arranged inside the central shaft ( 1 ).

The invention relates to a cooled mandrel for winding a band-typeproduct into a coil, in particular a metal band.

The invention applies especially to the winding of thin continuous-castband, but may be used, generally, for the winding into a coil of anyband at high temperature, liable to disturb the operation of themandrel.

In metallurgical plants, in particular rolling plants or metal bandprocessing plants, it is often necessary, at the outlet of a portion ofthe plant, to wind the band into a coil in order to transport it easilytowards another portion of the plant or any other processing station.

To do so, a winder is used, comprising a mandrel composed of acylindrical bar driven into rotation around its axis and fitted withmeans for fastening the end of the band which winds then into a coil onthe cylindrical bar.

Generally, the winding bar has a variable diameter and may be retractedto enable the removing of the coil after winding.

To this end, the mandrels used conventionally are of the type comprisinga supporting shaft centred on an axis and associated with rotationaldriving means, and a plurality of circular segments forming togethersubstantially cylindrical a surface and attached to the centralsupporting shaft with a possibility of radial displacement in order toenable the variation in diameter of the cylindrical surface thuscomposed and whereon is wound the band.

To control the variation in diameter of the mandrel, one usesconventionally a rack-type device, comprising a control part slidingaxially on the central shaft and whereon is arranged, for each segment,at least one conical portion co-operating with at least one matingtilted face arranged on an internal face of segment, which may thus moveaway from or come closer to the central shaft by longitudinaldisplacement of the control part under the action of an expansion rodmounted slidingly axially in a bore of the central shaft.

For correct operation of the mandrel, the different part in relativemotion should be able to move with minimum friction. Lubrication of thecontact surfaces of the parts in relative motion is therefore dedicatedto this end.

Until now, such mandrels have been used essentially in rolling plantsand the holding time of a coil on a mandrel is then rather limited anddoes not exceed 5 to 6 minutes, for instance. Even when the rolled bandis hot, such a holding time does not raise, normally, any thermalproblems liable to disturb the operation of the mandrel.

For some time, however, it has been sought to develop new continuouscasting technologies for very thin bands and it may be interesting, towind such a band into a coil on a mandrel.

Still, shortly after casting, the band is still at high temperature and,on the other hand, the winding time and, consequently, the holding timeof the coil on the mandrel may be long since it is linked to the castingspeed which is, obviously, much slower than that encountered in rollingplants.

Still, the mandrels used conventionally may not sustain such a heattransmission, by reason of the thermal effects, in particularconstraints and dilatations of the different parts, liable to disturbthe operation.

To solve this problem, the applicant company has suggested, recently, torealise a mandrel whereof the winding surface may be cooled bycirculating a heat exchanging fluid.

In such an arrangement, described in the document FR-A-2.761.964, theexternal face of each segment is composed of a curved plate, relativelythick, inside which is provided a cooling circuit having an inletorifice and an outlet orifice connected respectively to a supply ductand to an exhaust duct arranged at least partially, inside the centralshaft whereon are mounted the segments. To enable the expansion and theretraction of the mandrel by radial sliding of the segments, the inletand outlet orifices of the fluid are connected each, by a ductilefitting, to a chamber, respectively a supply chamber or an exhaustchamber, wherein emerges the corresponding duct.

In the arrangement of the document FR-A-2.761.964, the supply andexhaust chambers connected respectively to each segment are arranged ina fluid box attached to a front end of the central shaft which, usually,is mounted rotatably on a supporting chassis and extends cantilever froma rear end whereon is applied a rotational driving torque.

However, as already stated, the radial displacement of the segments forthe expansion or the retraction of the mandrel is controlled usually bya tubular part mounted slidingly on the central shaft of the mandrel andwhereof the displacement, in one direction or in the other, isdetermined by a control expansion rod mounted slidingly axially in abore of the central shaft. The tubular part must therefore be connectedto this control rod by a linking part which runs before the front end ofthe central shaft and may be displaced alternately in one direction orin the other for controlling the expansion or the retraction of thesegments. However, the latter may not move in the longitudinal directionand the same goes for the water box which, in the arrangement of thedocument FR-A-2.761.964 is connected to each segment by ductile fittingswhereof the length may vary radially. It is therefore necessary toprovide, between this water box and the front end of the central shaft aspace enabling the displacement of the part linking with the expansionrod and the supply and exhaust ducts arranged inside the central shaftshould therefore be connected to the corresponding chambers of the waterbox by ductile or sliding connection means.

It is therefore rather difficult, in such an arrangement, to guaranteethe tightness of the cooling circuit. Moreover, the segments areprolonged beyond the front end of the central shaft in order to providea housing wherein is placed the water box, the latter being connected tothe end of the central shaft by rods going through the linking part toenable the displacement axial thereof. Still, the ductile linkingfittings between each segment and the water box exert thereon, in theradial direction, significant loads, and which are not always equal.Moreover, in a metallurgical plant, in particular a continuous castingplant, the mandrel may be subjected to shocks and the water box, thusplaced at the end of the mandrel forms rather brittle a member.

The purpose of the invention is to solve such problems, while keepingthe advantages of the cooled mandrel described in the documentFR-A-2.761.964, thanks to a simpler arrangement of the cooling circuitenabling, besides, better protection of the supply and exhaust membersof the heat exchanging fluid.

Besides, the invention facilitates the disassembly of the mandrel formaintenance purposes and also enables to guarantee simply thelubrication of the different parts in relative motion.

The invention applies therefore, generally, to a cooled mandrel forwinding a product into a band comprising a central shaft extendingbetween a rear end connected to rotational driving means round an axisand a front end, and a set of adjacent segments mounted to slideradially on said shaft and having curved external faces which connect toform substantially cylindrical a winding surface centred on the axis ofthe central shaft, means for controlling a variation in diameter of thewinding surface, by radial sliding of said segments, between an expandedposition and a retracted position, and means for cooling the surface ofeach segment by circulating a heat exchanging fluid comprising, for eachsegment, a cooling circuit arranged inside said segment and having aninlet orifice and an outlet orifice of the heat exchanging fluidconnected each, by means of a deformable fitting, to a fluid supply orexhaust duct, respectively.

According to the invention each supply or exhaust duct, respectively isarranged, at least partially, inside the central shaft and is fitted,close to the front end thereof, with a bent portion extendingtransversally to the longitudinal axis (X′, X) of the central shaft andemerging on a lateral face of said shaft by a supply or exhausttransversal orifice, respectively, which is connected sealingly, by atleast one fitting of variable length, to at least one inlet or outletorifice, respectively, of at least one segment.

According to another particularly advantageous characteristic of theinvention, the fittings linking with the inlet and outlet orifices ofeach segment are attached to a distribution part in the form of a ringhaving a concave internal face threaded sealingly on a smooth bearingsurface of the lateral face of the central shaft, whereon are providedat least two internal orifices which, in the threaded position of thedistribution part, are aligned each with a supply or exhaust transversalorifice, respectively, opening onto said bearing surface of the centralshaft, in order to form substantially watertight a connection, and anexternal face whereon are provided, for each segment, two externalorifices, respectively a supply orifice and an exhaust orifice,associated each to a means for connecting a fitting linking with aninlet or outlet orifice, respectively of the corresponding segment, eachexternal orifice, respectively the supply orifice or the exhaustorifice, being connected to an internal orifice, respectively supply orexhaust, by at least one channel arranged, at least partially, in thedistribution part.

In a preferred embodiment, the mandrel comprises for each segment, apair of ducts, respectively a supply duct and an exhaust duct, arrangedinside the central shaft and emerging respectively, on the smoothbearing surface of the shaft, by a pair of transversal orifices, bothexternal orifices, respectively the supply orifice and the exhaustorifice, corresponding to each segment are connected by two channelsarranged in the distribution part, to two internal orifices,respectively the supply orifice and the exhaust orifice, and the pairsof internal orifices corresponding to the different segments aredistributed, along the internal face of the distribution part, similarlyto the pairs of transversal orifices on the smooth bearing surface ofthe shaft, so that, in the threaded position of the distribution part,each internal orifice, respectively the supply orifice or the exhaustorifice, lies in the extension of a transversal orifice connected to aduct, respectively the supply duct or the exhaust duct, of the centralshaft.

The mandrel comprising a number (n) of segments centred on radial planesdistributed starwise around the axis, the central shaft is thereforefitted with (n) pairs of ducts, respectively supply and exhaust ducts,extending symmetrically on both sides of each radial medial plane andemerging each into the smooth bearing surface of the shaft by atransversal orifice having an axis parallel to said radial medial planeand the internal and external orifices of the distribution part aredistributed by symmetrical pairs with respect to the radial medial planeof each segment and have axes parallel to said radial medial plane andaligned with the axes of each corresponding pair of transversal orificesof the smooth bearing surface of the central shaft.

Particularly advantageously, the smooth bearing surface of the centralshaft and the mating internal face of the distribution part are in theform of cylinders whereof the revolution is centred on the axis of thecentral shaft and having the same diameter, within the assemblyclearance, the distribution part being threaded slidingly on the smoothbearing surface of the shaft with interposition of at least two circularsealing joints on both sides of the aligned orifices.

In such a case, the external face of the distribution part includes,preferably, a plurality of connection facets, of number equal to thenumber (n) of segments, fitted each with a pair of external orifices,respectively supply and exhaust orifices, connected to a pair oforifices, respectively inlet and outlet orifices, of the correspondingsegment, by a pair of fittings of variable length having each aninternal end and an external end attached, respectively, on a facet ofthe distribution part and on a connection facet of the segment whereonare provided the inlet and outlet orifices of the fluid.

Each fitting of variable length may advantageously be composed of atubing of ductile material, such as an elastomer.

In a manner known in itself, the radial sliding of the segments iscontrolled by a rack-type device including a tubular sheath mounted toslide axially on the central shaft between two positions, respectively aretracted position and an extended position, and connected to a controlrod mounted slidingly in an axial bore of said shaft, by a linkingmember extending transversally before the front end of the centralshaft.

According to another particularly advantageous characteristic of theinvention, the tubular sheath whereon are arranged the tilted facescontrolling the radial sliding of the segments extends substantially, inits forward position, up to the insertion bearing surface of thedistribution part, and is prolonged, beyond the latter, by at least twoarms running each between two pairs of linking fittings between thedistribution part and both corresponding adjacent segments, in order tobe attached, by a front end, to the transversal member linking with thecontrol rod of the sliding.

The mandrel comprising (n) segments surrounding the central shaft, thedistribution part comprises itself (n) lateral watertight connectionfacet, each for a pair of linking fittings, between which are arranged(n) slipping faces forming each a sliding rest on an arm controlling thetubular sheath.

Preferably, the external face of the distribution part is substantiallypolygonal in shape, the lateral connection facet of the fittings beingplanar.

According to a preferred characteristic, the transversal linking memberbetween the control rod and the sheath is composed of a massive part,fitted with a central recess which, at least in a rear position of thecontrol rod, is mounted on a centring bearing surface, arranged betweenthe front end of the central shaft and the insertion bearing surface ofthe distribution part.

In certain cases, the linking member may advantageously be prolonged,towards the front, by a protruding portion forming an axle journalcentred on the axis of the central shaft and liable to rest, by means ofa bearing, on a fixed portion. Thus, instead of extending cantileverfrom the supporting chassis, the central shaft may rest, by removablemeans, on a fixed portion, which enables to avoid the flexion of thecentral shaft and to guarantee correct winding of the spires over oneanother.

On the other hand, the utilisation, according to the invention, of atubular sheath connected to the transversal member linking with thesliding control rod by arms running between the linking fittings,enables to implement a very simple lubrication system of the parts inmotion.

Indeed, according to a particularly advantageous arrangement, themandrel comprises a circuit for lubrication, at least, tilted facescontrolling the sliding of the segments comprising, for each tiltedface, at least one grease outlet orifice, situated at the exit of apipework extending along the sheath and prolonged along at least one armcontrolling the sliding up to a supply orifice, placed on the front endof said arm and connected, by fastening the linking member on said arm,to a watertight connection tubing, carried by the linking member, andconnected to a pressurised grease injection means.

Preferably, each connection tubing of the lubrication circuit isarranged on a rear face of the linking member, whereon applies the frontend of the corresponding control arm of the sheath and is placed at theexit of a conduit extending, at least partially, inside the linkingmember, up to a grease infeed orifice.

For watertight supply of the lubrication circuit, even under highpressure, the front end of the control rod which is centred on the axisof the mandrel is fitted with a cylindrical bearing surface which isinserted into a mating bore arranged at the centre of the linking partand wherein emerges at least a grease inlet orifice connected by aconduit to a connection tubing carried by the linking part, and thecontrol rod is fitted with at least one conduit extending longitudinallybetween a rear orifice connected to the grease infeed means and a frontorifice arranged on the insertion bearing surface of the control rod,and communicating with the grease inlet orifice emerging into the boreof the linking part, after inserting the control rod therein.

Advantageously, the insertion bearing surface of the control rod isfitted with at least one annular groove which, in the inserted positionof the control rod, is situated by the grease infeed orifice openingonto the central bore, said groove being surrounded by two annularjoints providing the tightness of the connection thus formed.

The invention also exhibits other advantages and covers othercharacteristics, mentioned in the claims, which will appear in thefollowing description of a particular embodiment, given forexemplification purposes and illustrated by the appended drawings.

FIG. 1 shows two semi-views in longitudinal section of the mandrelaccording to the invention, respectively in expanded position at theupper portion and in retracted position at the lower portion.

FIG. 2 shows two semi-views in horizontal section along the line II-IIof FIG. 1, respectively in expanded and retracted position.

FIG. 3 shows two semi-views in transversal section along the lineIII-III of FIG. 1.

FIG. 4 is a partial semi-view of the front end of the mandrel inlongitudinal section along the line IV-IV of FIG. 5.

FIG. 5 is a transversal sectional view along the line V-V of FIG. 4, inretracted position at the upper portion and in expanded position at thelower portion.

FIG. 6 is another partial view of the front end of the mandrel, inlongitudinal section along the line VI-VI of FIG. 5.

FIG. 7 is a partial view, in longitudinal section, along the lineVII-VII of FIG. 8, of the rear end of the central shaft.

FIG. 8 is a transversal sectional view along the line VIII-VIII of FIG.7.

FIG. 9 shows two semi partial views, in longitudinal section, of thefront end of the mandrel.

FIG. 10 is a front view of the linking part.

FIG. 11 is a partial view, from beneath, of the tubular control part.

FIG. 12 shows two semi-views in transversal section along the lineXII-XII of FIG. 1, respectively in expanded and retracted position.

FIG. 13 is a partial view, in longitudinal section, of a variation ofthe front end of the mandrel.

As indicated, the mandrel according to the invention comprises,generally, a central shaft 1 mounted rotatably on a chassis 10 aroundtwo bearings 11 and surrounded by a set of segments 2 mounted to slideradially on the central shaft and having curved external faces whichconnect tangentially to form a winding cylindrical surface centred onthe axis X′X of the shaft; the radial sliding of the segments iscontrolled by a tubular part in the form of a sheath 3, mounted on thecentral shaft and fitted with tilted faces 31 which co-operate withcorresponding tilted faces 21 of each segment 2 to determine theexpansion or the retraction of the mandrel by longitudinal displacementof the tubular sheath 3 between two positions, respectively a retractedposition and an expanded position, under the action of an expansioncontrol rod 4 sliding in an axial bore of the central shaft 1 andconnected to the tubular part 3 by a transversal linking member 40.

All these arrangements are well known and do not require a detaileddescription. Consequently, the drawings only show, on FIG. 1, the frontportion of the shaft 1 carrying the segments 2 and, on FIG. 7, the rearportion of the shaft 1 whereto are associated rotational driving meansnot represented on the drawing and a jack 41 controlling the axialsliding of the expansion rod 4.

Besides, the mandrel is of the type described in the previous patentFR-B-2.761.964, comprising means for cooling the winding surface bycirculating a heat exchanging fluid inside each segment. To this end,each segment 2 comprises therefore a curved external wall 20, relativelythick, inside which is arranged a cooling circuit 24, 24′ comprising aninlet orifice 75 and an outlet orifice 75′ connected respectively, byfittings of variable length 7, 7′, to supply 5 and exhaust 5′ ductsarranged inside the central shaft.

Advantageously, each fitting of variable length 7,7′ is composed of atubular sleeve of ductile material such as an elastomer, but it would bealso possible to use a telescopic assembly.

As seen above, in the arrangement known previously, the ductile fittingswere connected to a distribution box placed before the front end of thecentral shaft and separate therefrom by a space enabling thelongitudinal displacement of the linking member, each segment beingprolonged beyond the front end of the central shaft in order to providea housing wherein was placed the distribution box.

In the arrangement according to the invention, conversely, thedistribution box of the fluid 6 is mounted on the shaft 1 and comprisesa set of channels 65, 65′ placed in the alignment of channels 52, 52′,arranged radially in the thickness of the central shaft 1 and emergingeach, onto the lateral face 13 thereof, by an orifice, respectively asupply orifice 53 or an exhaust orifice 53′, said channels 65, 65′ beingconnected, by ductile fittings 7, 7′ with the orifices, respectively theinlet orifice 75 or the outlet orifice 75′, of the correspondingsegment. This distribution box 6 is therefore placed behind the linkingmember 40 which may move freely under the action of the expansioncontrol rod and the segments 2 extend over a length substantially equalto that of the central shaft.

In particular, in the preferred embodiment represented, on FIGS. 4 and5, the central shaft 1 is fitted, for each segment 2, with two boresparallel to the axis, which extend over the whole length of the shaft 1and form respectively a supply duct 5 and an exhaust duct 5′ arrangedsymmetrically on both sides of the medial plane P of the segment 2. Inthe case, represented on the figure, of a mandrel including foursegments each covering a quadrant, the central shaft 1 is hence fittedwith four pairs of ducts 5, 5′.

As before, the linking member 40 which is attached to the front end ofthe expansion control rod 4 extends transversally before the front face12 of the central shaft 1. However, in the previous arrangement of theFrench patent 2 761 964, the supply and exhaust ducts arranged in thecentral shaft should be prolonged by tubings running through the linkingmember, for connection to the distribution box placed before saidmember. In the arrangement according to the invention, conversely, thelongitudinal bores forming the ducts 5, 5′ are sealed, each, by a plug51, at the front face 12, and communicate with a channel 52, 52′ whichextends transversally to the axis X′X of the mandrel to emerge via anorifice 53, 53′ opening onto a front portion 13′ of the lateral face 13of the shaft 1.

In the preferred embodiment represented on the figures, the lateral face13 of the shaft 1 whereon is mounted the control part 3 in the form of atubular sheath is fitted, on its front portion 13′, with a smoothbearing surface having a cylindrical revolution section and whereon ismounted a distribution part in the form of a ring 6 having a concaveinternal face 61 of diameter equal, within the assembly clearance, tothat of that smooth bearing surface 13′.

On the other hand, the distribution part 6 is limited by an externalface 62 including, for each segment 2, a facet, preferably planar, forfastening ductile linking fittings between the segment 2 and the supply5 and exhaust 5′ ducts. In the four-segment embodiment represented onthe figures, the external face 62 of the distribution part 6 hastherefore a square section in order to exhibit four planar connectionfacets, each, with a pair of ductile fittings 7, 7′. For, each segment2, the distribution ring 6 is fitted, on its internal face 61, with twointernal orifices 63, 63′ which communicate each with an externalorifice 64, 64′ arranged on the external face 62, by a channel 65, 65′drilled in the thickness of the ring 6.

Moreover, as shown on FIG. 5, these linking channels 65, 65′ between theinternal orifices 63, 63′ and the external orifices 64, 64′ are centredon axes orthogonal to the axis X′X of the shaft 1 and parallel to themedial plane P of the corresponding segment 2 and are thereby aligned,in the threaded position of the ring 6, with the axes of the channels52, 52′ which run through the shaft 1 to communicate with the duct,respectively the supply duct 5 or the exhaust duct 5′.

Preferably, the smooth bearing surface 13′ arranged on the front portionof the shaft 1 has a diameter smaller than that of the lateral face 13thereof in order to former a countersink enabling to insert of thering-shaped distribution part 6, up to a set position for which thechannels 52, 52′ of the shaft 1 and 65, 65′ of the ring 6 are perfectlyaligned, the ring 6 being maintained in this position by a stop 15.

On the other hand, each external orifice 64, 64′ of the ring 6 emergesinto a deformable fitting 7, 7′ attached by a drilled plate forming aninternal flange 71 on a corresponding facet 62′ of the external face 62of the ring. Similarly, at their opposite end, both fittings 7, 7′ areattached by an external flange 71′ to a planar facet 73 arranged on theinternal side of a connection part 70 in the form of a circular sectorattached to the front end of each segment 2.

Advantageously, an intermediate plate 72 is interposed between theexternal flange 71′ and the connection part 70 of the segment in orderto facilitate the disassembly of the segment, as can be seen thereunder.

As usual, each segment 2 comprises an external portion 20 in the form ofa cylindrical revolution sector which forms a portion of the windingsurface of the band and an internal portion 20′ whereon are arranged thetilted faces 21 co-operating with the mating faces 31 of the tubularsheath 3 to control the expansion or the retraction of the mandrel.

In the preferred embodiment represented on the figures, the externalportion 20 of the segment 2 is composed of a curved plate in thethickness of which are arranged two series of channels, respectively 24,24′ parallel to the axis X′X of the mandrel and extending, respectively,on both sides of the medial plane P of the segment, said channels beingregularly spaced apart in order to cover substantially the whole surfaceof the segment.

As can be seen on FIG. 4, the front end of the segment 2 is fitted withtwo circular grooves 25, 25′ wherein emerge, respectively, both seriesof channels 24, 24′. On the other hand, the connection part 70 which isattached, as seen above, to the front end of the curved plate 20, isfitted itself with two oblong holes 74, 74′ which open each, on one sideonto a portion of the corresponding groove 25, 25′ of the segment 2 andon the other side, into a channel 76 arranged in the thickness of theconnection part 70 and emerging via an orifice 75, 75′ onto the planarfacet 73 whereon is applied the external flange 71′ for fastening thepair of fitting 7, 7′.

Moreover, as shown on FIG. 1, the rear end of each curved plate 20 isfitted with a circular groove 23 which joins both series of channels 24,24′ and is closed outwardly by a plug.

Conventionally, the shaft is fitted with a transversal flange 14engaging into a housing arranged at the back of each segment 2 which ismaintained by an axial stop 27 with a possibility of radial sliding.Both orifices 75, 75′ arranged in the connection part 70 remaintherefore aligned with the transversal channels 52, 52′ whereto they areconnected by the ductile fittings 7, 7′ which follow the expansion orretraction movements of the segment.

Inserting the ring 6 on the smooth bearing surface 13′ with a simpleassembly clearance guarantees a watertight link between the channels 52,52′ and 65, 65′, of the annular sealing joints 16 thereby avoiding waterleaks inside the mandrel.

Thus, the heat exchanging fluid incoming via the supply duct 5 runssuccessively through the channel 52, the ductile fitting 7 and the inletorifice 75, to emerge via the oblong hole 74 in the groove 25 in orderto spread in the set of channels 24. At the rear end of the segment 2,the fluid runs through the rear groove 23 to come back through theexhaust channels 24′ and then runs through the oblong hole 74′, theoutlet orifice 75′, the ductile fitting 7′ and the channel 65′ to emergeinto the exhaust duct 5′.

The ring 6 form thus a fluid distribution box, via ductile fittings 7,7′, between each segment 2 and the ducts, respectively the supply duct 5and the exhaust duct 5′, arranged in the central shaft 1.

Thanks to the invention, this distribution box 6, threaded on the frontportion of the central shaft 1 and placed behind the linking member 40,is perfectly protected against possible shocks. However, connection mustbe guaranteed between this linking member 40 and the control part 3 forthe expansion and the retraction of the segments which is composed, asusual, of a tubular sheath threaded on the lateral cylindrical face 13of the shaft 1 and whereof the length is limited in order to extend onlyup to the bearing surface 13′ for inserting the distribution ring 6, inthe forward position of the sheath corresponding to the retraction ofthe segments.

To this end, according to another particularly advantageouscharacteristic of the invention, the tubular sheath 3 controlling theexpansion and the retraction of the segments extends, in its forwardposition, up to the bearing surface 13′ for inserting the distributionring 6, and is prolonged towards the front, beyond thereof by at leasttwo arms 32 which run each in a space left between two pairs of ductilefittings 7, 7′ and prolong each up to the front end 15 of the shaft 1,so that the linking member 40 with the expansion control rod 4 may beattached, by bolts 34, to the front face 33 of said arms 32 (FIG. 2).

Thus, as shown on FIG. 5, in the four-segment embodiment, the tubularsheath 3 is prolonged by four linking arms 32 laid out starwise andcentred each on a junction plane P′ between two adjacent segments, inorder to run between the ductile fittings 7, 7′ corresponding to eachsegment.

Preferably, the linking member 40 is composed of relatively massive apart, in the form of a bell, comprising a central recess 42 which, atleast in a rear position of the control rod 4 corresponding to theexpansion of the mandrel, is mounted on a centring bearing surfacearranged between the front end 12 of the central shaft and thedistribution ring 6. As shown on the figures, this centring bearingsurface 15′ may advantageously be composed of the lateral face of thelocking flange 15 of the distribution ring 6.

The central portion 43 of the linking member 40, which forms the bottomof the recess 42, is drilled with a bore 44 wherein is inserted the end44′ of the control rod 4, the latter being prolonged by a bolt 45 fittedwith a tightening nut.

Thus, the rod 4 sliding axially in the central shaft 1 and connected tothe tubular sheath 3 by the transversal linking member 40 and the arms32 may control the expansion or the retraction of the mandrel by radialdisplacement of the segments 2. As already indicated, the wholedistribution system of the heat exchanging fluid in the differentsegments, placed between the front end of the segments 2 and the massivepart 40 forming the linking member with the control rod 4 is perfectlyprotected against the shocks. Moreover, all the members of the fluidcirculation system are interconnected, axially, with the central shaft 1and may be attached sealingly, either to the latter, or to the differentsegments 2 by means of the ductile fittings 7, 7′. This arrangementenables therefore to guarantee the distribution of the heat exchangingfluid in the different segments with a perfect tightness without usingany flexible hoses.

Indeed, as shown on FIGS. 3 and 5 relative to a four-segment assembly,the central shaft 1 may be drilled, over its whole length, with eightlongitudinal bores spaced regularly around the axis and arranged inpairs in order to form, for each segment a supply channel 5 and anexhaust channel 5′ extending symmetrically on both sides of the medialplane P of the segment and communicating each, by a transversal channel52, 52′ with a ductile fitting 7, 7′ linking with an inlet or outletorifice, respectively of the fluid, arranged on the connection part 70of each segment.

As indicated on FIGS. 7 and 8, the supply and the exhaust of the heatexchanging fluid may be performed similarly to the manner described inthe previous patent No. 2 761 964, by a revolving seal 54 composed of asocket-shaped part threaded on the rear portion of the shaft 1 andincluding, on its internal face, two circular grooves connectedrespectively to fluid supply and exhaust means and communicating, viatransversal tubings 55, 55′, with the bores forming, respectively, thesupply 5 and exhaust 5′ channels.

But the arrangement according to the invention also shows otheradvantages.

First of all, since the fluid distribution system is placed behind thelinking member 40, it is possible to provide the front end of thecentral shaft 1 of the mandrel in order to enable said mandrel to resttransversally on a fixed portion.

Indeed, as shown on FIG. 13, the part 40 forming the transversal linkingmember may be prolonged towards the front by a protruding centralportion 43′, forming a kind of axle journal whereon may be inserted abearing 17 through which the shaft 1, which revolves around its axis,may rest on a fixed portion, not represented.

It is thus possible to dispense with the flexion of the shaft under theweight of the coil and, thus, to guarantee contiguous winding of thespires superimposed.

However, if the weight of the coil once wound, as well as the tensionapplied to the band, are not excessive, the shaft of the mandrel may, asusual, extend cantilever from the supporting chassis 10. In such a case,it is advantageous to cover the front end of the mandrel by a protectioncover 26 attached removably to the linking member 40 and extendingtowards the rear in order to cap the assembly of said linking member 40.Similarly, each segment 2 may be prolonged towards the front by a curvedplate 26′ having a diameter slightly smaller than that of the cover 26in order to reach inside said cover with a possibility of longitudinalsliding over the length corresponding to the axial displacement of theexpansion control rod 4. There is thus provided a protection coversubstantially continuous against dusts or other external nuisances,enabling to prevent pollution of the inside of the mandrel.

But the invention also enables to provide simple and efficiencylubrication of the different portions of the mandrel.

It is necessary, indeed, to lubricate the parts in contact and, inparticular, the mating tilted faces 31, 21 which perform the expansionand the retraction of the mandrel. To this end, each tilted face 31 ofthe sheath 3 is fitted with a grease outlet orifice 80 which, thanks tothe invention, may be connected, by means of the linking member 40, toat least one channel 8 arranged over the whole length of the expansionrod 4 and connected to a grease supply means 48, attached to the rearportion of the mandrel.

As shown in particular on FIG. 1, each grease outlet orifice 80 issituated at the exit of a pipework whereof at least one portion isdrilled inside the tubular sheath and may be prolonged at the outsidethereof, by a duct 81 extending along the sheath and connectingsealingly to a channel 82 drilled inside a linking arm 32 (FIG. 6) andemerging, on the front face 33 of said arm, through an orifice 83 which,after fastening the linking member 40 on the arms 32 using the bolts 34,is connected sealingly to a tubing 83′ arranged on the linking part 40and emerging onto the rear face thereof.

As shown on FIGS. 9 and 10, this tubing 83′ is connected by a channel 84extending radially inside the linking member 40, to a grease infeedorifice 85 opening onto the internal face of the axial bore 44 whereinis inserted the front end of the expansion rod 4 which forms acylindrical bearing surface 44′ whereon is arranged a circular groove 46which communicates, by a transversal channel, with the supply channel 8arranged inside the expansion rod 4.

As indicated, the central bore 44 of the linking member 40 forms acountersink enabling to lock the linking member 40 in a fixed positionfor which the grease infeed orifice 85, opening onto the bore 44, issituated close to the groove 46.

This groove 46 is surrounded by two annular joints in order to provide awatertight pressurised link between the supply channel 8 and the greaseinfeed orifice 85.

In a known fashion, as shown schematically on FIG. 7, the rear end ofthe control rod 4 is connected to the stem of the expansion orretraction control jack 41 of the mandrel, by a coupling member 47 whichguarantees, moreover, watertight link, by a circuit not represented,with a pressurised grease supply means 48 integral with the jack 41.

Thus, the grease injected through the pipework 8 drilled in the controlrod 4 runs through, in succession, the linking member 40 and one of thearms 32 of the sheath to emerge into at least one orifice 80 arranged onat least one tilted face 31.

To control a radial displacement, parallel to itself, of each segment,the tubular sheath 3 includes at least two series of tilted faces 31centred respectively on two mean transversal planes spaced apartlongitudinally and co-operating with at least two series of tilted faces21 arranged on the internal side of the segment 2.

For example, in the case represented on the figures, the sheath 3 andthe segments 2 include three series of tilted faces 31, 21 spaced apartlongitudinally. The arrangements according to the invention enable thedistribution of the grease, from the same axial channel 8, on the set ofthe tilted faces 31. Indeed, as shown on FIGS. 9 and 10, a groove 46communicating with the channel 8 may supply several orifices 85 emergingonto the internal face of the bore 44 and connected each, by a channel84, to a channel 82 going through an arm 32 and prolonged by a duct 81which may be composed partially of an external pipework extending alongthe external face of the sheath 3, between the protruding portions 30carrying the tilted faces 31. This pipework 81 emerges advantageouslyinto a fork placed at the medial plane of a series of tilted faces to bedivided into at least two branches 86 connected each to an outletorifice 80 arranged on either of the tilted faces 31 of this series.Each arm 32 may, possibly, be drilled with several channels 82 and, forinstance, if the sheath 3 is fitted with four arms 32 of the mannerrepresented on the figures, it is easy to distribute a sufficient numberof supply ducts on the sheath 3 in order to supply with grease all thetilted faces 31 controlling the expansion or the retraction of themandrel.

Moreover, as shown on the figures, other pipeworks 87 connected to thelongitudinal channel 82, may also be arranged in the linking member 40or the tubular sheath 3 in order to grease other portions of themandrel.

The arrangement according to the invention also enables to implement acentralised lubrication system of the different portions of the mandrel.

To this end, in the preferred embodiment represented on the figures, thecontrol rod 4 is fitted with two axial channels 8, 8′ which communicaterespectively with two grooves 46, 46′ arranged on the cylindricalbearing surface 44′ of the front end of the rod. As shown on FIG. 10,both grooves 46, 46′ may supply, respectively, two groups of channels84, 84′ which are connected in pairs to distributors 89 enabling tosupply either of both groups of pipeworks 82, 81, 81′ arranged in thearms 32 or along the tubular sheath 3 and connected to certain tiltedfaces 31 of the sheath 3, said faces being thus spread into two groupswhich may be supplied alternately, thanks to a centralised lubricationsystem, from either of the supply channels 8, 8′, running through thecontrol rod 4.

It should be noted that the lubrication circuits may be providedpractically totally by drillings arranged in machined parts and thatfittings are dispensed with. Indeed, in the embodiment represented onthe drawings, only the rigid pipeworks 81, 86 extend outside the sheath3, no flexible hoses being necessary to enable the sliding of the sheathand of the segments.

But, another important advantage of the invention lies in the fact thatthe whole mandrel may be dismantled easily for maintenance purposes orreplacing certain parts.

It should be noted, indeed, that the cooling segments 2, which are incontact with the band to be wound, form a kind of wear part, even ifthey have been designed to hold as long as possible. Consequently, it isadvantageous to be able to replace the cooling segments withoutdismantling the whole mandrel.

To do so, as indicated above, the external flange 71′ of each pair ofdeformable fittings 7, 7′ is attached to an intermediate plate 72 which,is itself attached to the connection part 70 of the segment 2 by holdingscrews 76 which may be withdrawn from the outside. The external portion20 of each segment 2 may thus be withdrawn and replaced while leaving inplace all the other parts of the mandrel, and in particular, thedistribution ring 6 and the deformable fittings 7, 7′.

But it is also possible to change the deformable fittings, which aremade of a flexible material, such as an elastomer, without needing todismantle the mandrel.

To do so, it suffices to withdraw the front cover 26 and to unscrew thebolts 45, 34, fastening the linking member 40, respectively to thecontrol rod 4 and to the arms 32, in order to remove the linking member40 and access the distribution box 6 which may thus be dismantled as asingle piece with the four pairs of deformable fittings 7, 7′ and theplates 72.

In this view, the machining operations performed at the four corners ofthe ring 6 enable to maintain and guide said ring between the four arms32 of the sheath 3 during disassembly, the latter operation beingperformed in retraction position of the mandrel. Thus, once cleared fromthe spindle 13′, the water box 6 remains held between the arms 32 of thesheath 3. Conversely, during re-assembly, the mandrel is expanded and itis the linking member 40 with the back-up ring 15 which pushes the waterbox 6 to the smooth bearing surface 13′, up to the bottom of thecountersink, in a set position for which the orifices of the watercirculation systems are aligned.

The assembly composed of the distribution box 6 and of the deformablefittings 7, 7′ with the intermediate plates 72 forms therefore acomplete mechanical sub-assembly, which can be dismantled in situ simplyafter removing the linking member 40. A deformable fitting may thus bereplaced without needing to remove the whole mandrel.

However, the arrangements according to the invention also enable easydismantling of the whole the mandrel, in a single operation.

To do so, it suffices, indeed, to remove the axial stops 27 which, asseen above, interconnect axially the segments 2 with the flange 14 ofthe shaft 1, with a possibility of radial sliding.

After dismantling the front cover 26 and unscrewing the nut connectingthe expansion rod 4 to the linking member 40, it is possible todismantle the whole mandrel, in retracted position, by driving the waterbox 6 which is enclosed inside the arms 32 of the sheath 3.

Obviously, the invention is not limited to the details of the embodimentwhich has just been described for exemplification purposes and may besubject to variations using equivalent means, while remaining within theprotection framework defined by the claims.

For example, the mandrel might include a different number of segments.

On the other hand, to provide the cooling circuits, it is interestingthat each segment 2 includes sufficiently thick a wall to drill thereintwo series of fluid circulation channels. Still, each segment could alsobe of welded construction, as described in the previous patent No.2.761.964, the external wall of the segment comprising two curvedplates, respectively internal and external plates, spaced from oneanother in order to provide a free space divided, by at least one wallparallel to the axis, into at least two chambers, respectively supplyand exhaust chambers, which emerge respectively into an inlet orificeand an outlet orifice of the heat exchanging fluid opening onto aconnection facet arranged on the internal face of the segment, at an endthereof, and whereon may be plugged two ductile fittings 7, 7′. However,the preferred embodiment described above enables to resists better tohigh thermal loads to which the segments are exposed.

In particular, as represented on FIGS. 1 and 12, the curved plate 20forming the external portion of the segment wherein are provided thechannels 24, 24′ may be attached to the internal portion 20′ whereon arearranged the tilted faces 21, by a series of screws 28 placed in themedial axis of the segment and associated to keys 28′ which engage incorresponding housings of both portions 20, 20′ of the segment, in orderto transmit the band tension torque, with a longitudinal clearanceallowing dilatation of the segment.

Besides, the realisation of the cooling circuits by bores which may beplaced relatively close to the external surface, enables to adjustprecisely the extracted thermal flux by varying the water flow rate.

It should also be noted that, if it is particularly advantageous toprovide centralised lubrication as described above, the mandrel mightalso, in a simpler design, be greased manually. In such a case, it wouldnot be necessary any longer to provide the supply channels 8, 8′ in theexpansion rod 4 but the linking member 40 would still be provided as adrilled block enabling the distribution of the grease through thelinking arms 32 of the sheath, the distributors 89 being simply replacedwith individual lubrication bars, accessible via simple modification ofthe front cover 26.

The reference signs inserted after the technical characteristicsmentioned in the claims, solely aim at facilitating the understandingthereof and do not limit their extent in any way.

1. A Cooled mandrel for winding a band-type product into a coil,comprising a central shaft (1) extending between a rear end connected torotational driving means round an axis (X′X) and a front end, and a setof adjacent segments (2) mounted to slide radially on said shaft (1) andhaving curved external faces which connect to form substantiallycylindrical a winding surface centred on the axis (X′X) of the centralshaft (1), means (3,4) for controlling a variation in diameter of thewinding surface, by radial sliding of said segments (2), between anexpanded position and a retracted position, and means for cooling thesurface of each segment by circulating a heat exchanging fluidcomprising, for each segment, a cooling circuit (24, 24′) arrangedinside said segment (2) and having an inlet orifice (75) and an outletorifice (75′) of the heat exchanging fluid connected each, by means of afitting of variable length (7,7′), to a fluid supply (5) or exhaust (5′)duct, respectively, characterised in that each supply (5) or exhaust(5′) duct, respectively is arranged, at least partially, inside thecentral shaft (1) and fitted, close to the front end thereof, with abent portion (52, 52′) extending transversally to the longitudinal axis(X′X) and emerging on a lateral face (13′) of said shaft (1) via asupply (53) or exhaust (53′) transversal orifice, respectively, which isconnected sealingly, by at least one fitting of variable length (7, 7′),to at least one inlet (75) or outlet (75′) orifice, respectively, of atleast one segment (2).
 2. A winding mandrel according to claim 1,characterised in that the fittings of variable length (7, 7′) linkingwith the inlet (75) and outlet (75′) orifices of each segment (2) areattached to a distribution part (6) in the form of a ring having aconcave internal face (61) threaded sealingly on a smooth bearingsurface (13′) of the lateral face (13) of the central shaft (1), whereonare provided at least two internal orifices (63, 63′) which, in thethreaded position of the distribution part (6), are aligned each with asupply (53) or exhaust (53′) transversal orifice, respectively, openingonto said bearing surface (13′) of the central shaft (1), in order toform substantially watertight a connection, and an external face (62)whereon are provided, for each segment, two external orifices,respectively supply (64) and exhaust (64′) orifices, associated each toa means (71) for plugging a connection fitting (7) on an inlet (75) oroutlet (75′) orifice, respectively of the corresponding segment, eachexternal orifice, respectively a supply (53) or exhaust (53′) orifice,being connected to an internal orifice, respectively a supply (63) orexhaust (63′) orifice, via at least one channel (65) arranged, at leastpartially, in the distribution part (6).
 3. A winding mandrel accordingto claim 2, characterised in that it includes, for each segment (2), apair of ducts, respectively supply (5) and exhaust (5′) ducts, arrangedinside the central shaft (1) and emerging respectively, on the lateralface (13) of the shaft (1), via a pair of transversal orifices (53,53′), that each pair of external orifices, respectively supply (64) andexhaust (64′) orifices, corresponding to a segment is connected by twochannels (65, 65′) arranged in the distribution part (6), to a pair ofinternal orifices, respectively supply (63) and exhaust (63′) orifices,and that the pairs of internal orifices (63, 63′) corresponding to thedifferent segments are distributed, along the internal face (61) of thedistribution part (6), similarly to the pairs of transversal orifices(53, 53′) on the insertion bearing surface (13′) of the shaft (1), sothat, in the threaded position of the distribution part (6), eachinternal orifice, respectively the supply (63) or exhaust (63′) orifice,lies in the extension of a transversal orifice (53, 53′) connected to aduct, respectively the supply (5) or exhaust (5′) duct, of the centralshaft (1).
 4. A winding mandrel according to claim 3, comprising anumber (n) of segments (2) having a radial medial plane (P) andextending between two radial junction planes, said radial planes beingdistributed starwise around the axis (X′X), characterised in that thecentral shaft (1) is fitted with (n) pairs of ducts, respectively supply(5) and exhaust (5′) ducts, extending symmetrically on both sides ofeach radial medial plane P and emerging each into the lateral face (13)of the shaft (1) via a transversal orifice (53, 53′) having an axisparallel to said radial medial plane (P) and in that the internalorifices (63, 63′) and external orifices (64, 64′) of the distributionpart (6) are distributed by symmetrical pairs with respect to the radialmedial plane (P) of each segment and have axes parallel to said radialmedial plane and aligned with the axes of each corresponding pair oftransversal orifices (53, 53′) of the insertion bearing surface (13′) ofthe central shaft (1).
 5. A winding mandrel according to any of theclaims 2, 3, 4 characterised in that the lateral face (13) of thecentral shaft and the mating internal face (61) of the distribution part(6) are in the form of cylinders whereof the revolution is centred onthe axis (X′X) of the central shaft (1) and having the same diameter,within the assembly clearance, and that the distribution part (6) ismounted slidingly on the insertion bearing surface (13′) of the shaft(1) with interposition of at least two annular sealing joints (16), onboth sides of the aligned orifices (52, 65), (52′, 65′).
 6. A windingmandrel according to claim 5, characterised in that the external face(62) of the distribution part (6) includes a plurality of connectionfacets (62′), whereof the quantity is equal to the number (n) ofsegments, fitted each with a pair of external orifices, respectivelysupply (64) and exhaust (64′) orifices, connected to a pair of orifices,respectively inlet (75) and outlet (75′) orifices, of the correspondingsegment (2), by a pair of fittings of variable length (7, 7′) havingeach an internal end and an external end attached respectively to afacet (62′) of the distribution part (6) and on a connection facet (73)of the segment (2) whereon are provided the inlet (75) and outlet (75′)orifices of the fluid.
 7. A winding mandrel according to claim 6,characterised in that the ends, respectively internal and external ends,of the fittings (7, 7′) of each pair are attached respectively on theconnection facets (62′, 73) of the distribution part (6) and of thesegment (2), by two plates forming respectively an internal flange (71)and an external flange (71′).
 8. A winding mandrel according to claim 7,characterised in that the external flange (71′) for fastening is eachpair of fittings (7, 7′) on each segment (2) is attached to anintermediate plate (72) attached itself to the connection facet (73) ofthe segment (2) by screws (76) engaging from the outside.
 9. A windingmandrel according to any of the previous claims, comprising a number (n)of segments (2) and wherein the central shaft (1) extends between a rearportion connected to means for driving said shaft into rotation roundits axis, and a front portion for supporting the segments (2),characterised in that the radial sliding of the segments is controlledby a rack-type device comprising a tubular sheath (3) mounted to slideaxially on the front portion of the central shaft and whereon arearranged at least (n) faces (31) tilted with respect to the axis,co-operating each with a mating tilted face (21) of a correspondingsegment (2), for controlling, respectively, the expansion or theretraction of the mandrel by sliding the sheath (3) between twopositions, respectively a retracted position and an extended position,under the action of a control rod (4) mounted slidingly parallel to theaxis (X′X) of the central shaft (1) and prolonged beyond a front end(12) thereof in order to be attached to a linking member (40) with thetubular sheath (3), extending transversally before the front end (12) ofthe central shaft (1).
 10. A winding mandrel according to claim 9,characterised in that the tubular sheath (3) mounted slidingly on thecentral shaft (1) extends substantially, in its forward position, up tothe bearing surface (13′) for inserting the distribution part (6), andis prolonged, beyond the latter, by at least two arms (32) running eachbetween two pairs of connection fittings (7, 7′) between thedistribution part (6) and both corresponding adjacent segments, each arm(32) being attached, by a front end (33), to the transversal member (40)linking with the sliding control rod (4).
 11. A winding mandrelaccording to claim 10, comprising (n) segments (2) surrounding thecentral shaft (1), characterised in that the distribution part (6)comprises (n) watertight connection facets (62′), each of a pair ofconnection fitting (7, 7′), between which are arranged (n) slippingfaces forming each a sliding rest for an arm (32) controlling thetubular sheath (3).
 12. A winding mandrel according to claim 11,characterised in that the external face (62) of the distribution part(6) has a polygonal shape, the connection facet (62′) of the fittings(7, 7′) being planar.
 13. A winding mandrel according to any of theclaims 10 to 12, characterised in that the transversal linking member(40) between the control rod (4) and the sheath (3) is composed of amassive part, fitted with a central recess (42) which, at least in arear position of the control rod (4), is mounted on a centring bearingsurface (15), arranged between the front end (12) of the central shaft(1) and the insertion bearing surface (13′) of the distribution part(6).
 14. A winding mandrel according to claim 13, characterised in that,the control rod (4) being mounted slidingly in an axial bore of thecentral shaft (1), the central recess (42) of the transversal linkingmember (40), is closed towards the front by a bottom whereon is attachedthe front end of the control rod.
 15. A winding mandrel according toclaim 14, characterised in that the linking member (40) is prolonged,towards the front, by a protruding portion (44) forming a axle journalcentred on the axis of the central shaft and liable to rest, by means ofa bearing (17), on a fixed portion.
 16. A winding mandrel according toone of the claims 9 to 15, characterised in that it includes aprotection cover (26), attached removably to the linking member (40) andextending towards the rear, in order to cap the assembly thereof.
 17. Awinding mandrel according to claim 16, characterised in that eachsegment (2) is prolonged towards the front by a curved plate (26′)having a diameter slightly smaller than that of the cover in order (26)to reach thereinside with a possibility of longitudinal sliding to formsubstantially continuous a protection.
 18. A winding mandrel accordingto any of the previous claims, characterised in that each segment (2)comprises an internal portion (20′) supporting means controlling theradial sliding and an external portion (20) in the form of a cylindricalsector, of welded construction and comprising two curved plates,respectively internal and external, spaced apart from one another inorder to provide a free space divided, by at least one wall parallel tothe axis, into at least two chambers, respectively supply and exhaustchambers, wherein emerge, respectively, an inlet orifice and an outletorifice of heat exchanging fluid, arranged in the internal plate of thesegment, at an end thereof, said chambers being communicated at theother end of the segment.
 19. A winding mandrel according to any of theclaims 1 to 17, characterised in that each segment comprises an internalportion (20′) supporting means controlling the axial sliding and anexternal portion (20) in the form of a cylindrical sector, composed of acurved plate (20) in the thickness whereof are provided a plurality ofchannels (24, 24′) parallel to the axis of the mandrel and distributedover the whole surface of the segment in two series, respectively asupply series (24) and an exhaust series (24′), emerging each, at afront end of the segment, into a distribution chamber (25, 25′) integralwith the segment (2) and fitted with an inlet orifice (75) or an outletorifice (75′), respectively of the fluid, the channels (24, 24′) of bothseries being connected to one another, at a rear end of the segment, bya common distribution chamber (23).
 20. A winding mandrel according toclaim 10, comprising a number (n) of segment and wherein each arm (32)controlling the sliding of the sheath (3) is attached, by a front end(33), to a rear face of the transversal member (40) linking with thecontrol rod (4), characterised in that it includes a circuit forlubrication, at least, tilted faces (31) controlling the sliding of thesegments comprising, for each tilted face (31), at least one greaseoutlet orifice (80), situated at the exit of a pipework (81) extendingalong the sheath (3) and prolonged by a portion (82) along at least onearm controlling the sliding up to a supply orifice (83) placed on thefront end (33) of said arm (32) and connected, by fastening the linkingmember (40) on said arm (32), on a watertight connection tubing (83′),carried by the linking member (40), and connected to a pressurisedgrease infeed means (8, 48).
 21. A winding mandrel according to claim20, characterised in that each connection tubing (83) of the lubricationcircuit is arranged on a rear face of the linking member (40), whereonapplies the front end (33) of the corresponding control arm (32) of thesheath (3) and is placed at the exit of a conduit (84) extending, atleast partially, inside the linking member (40), up to a grease infeedorifice (85).
 22. A winding mandrel according to claim 21, wherein thecontrol rod is centred on the axis of the mandrel and attached, by afront end, on a transversal part forming the linking member (40) withthe sheath (3), characterised in that the front end of the control rod(4) is fitted with a cylindrical bearing surface (44′) which is insertedinto a mating bore (44) arranged at the centre of the linking member(40) and wherein emerges at least one grease inlet orifice (85)connected by a conduit (84) to the connection tubing (83′) carried bythe linking member (40), and that the control rod (4) is fitted with atleast one channel (8) extending longitudinally between a rear orificeconnected to the grease infeed means (48) and a front orifice arrangedon the insertion bearing surface (44′) of the control rod, andcommunicating with the grease inlet orifice emerging into the bore (44)of the linking part (40), after inserting the control rod (4) therein.23. A winding mandrel according to claim 22, characterised in that thebearing surface (44′) for inserting the control rod (4) is fitted withat least one groove (46) which, in the inserted position of the controlrod, is situated by the grease infeed orifice (85) opening onto thecentral bore (44), said groove (46) being surrounded by two annularsealing joints (49).
 24. A winding mandrel according to any of theclaims 20 to 23, comprising at least two series of tilted faces (31)controlling the radial displacement, respectively, of each segment (2),centred on two mean transversal planes spaced apart longitudinally, eachsegment (2) being associated with a face of each series, characterisedin that the lubrication circuit comprises, for each series of tiltedfaces (31), at least one pipework (82, 81) extending along a control arm(32), from a supply orifice (83) placed on the front end (33) of saidarm (32) up to a fork placed at said series of tilted faces, from whichsaid pipework (81) is divided into at least two branches (86) emergingeach into an outlet orifice (80) arranged on one of the tilted faces(31) of said series.
 25. A winding mandrel according to any of theclaims 23 and 24, characterised in that the tilted faces (31)controlling the radial sliding of the segments (2) are distributed intoat least two groups associated each a lubrication circuit, that thecontrol rod is fitted with at least two longitudinal channels (8, 8′)emerging each into a groove (46, 46′) of the insertion bearing surface(44′), that the central bore of the linking part is fitted with at leasttwo groups of orifices (85) coinciding, in the inserted position, eachwith a groove (46, 46′) of the insertion bearing surface (44′), andconnected each to a connection tubing (83′), that the tubular sheath (3)carries at least two groups of pipeworks (82, 81, 81′) associatedrespectively with said groups of tilted faces, each pipework (82)extending along a control arm (32), from a supply orifice (83) connectedto one of the connection tubings (83′), up to at least one grease outletorifice (80) emerging into at least one tilted face (31) of thecorresponding group, and that the mandrel is associated with acentralised lubrication system for controlling the pressurisedintroduction of grease, alternately, in either duct (8, 8′) of thecontrol rod (4) and the lubrication of either group of tilted faces(31).